How relevant is the DTM to F1?

Mercedes, Audi and BMW claim the FIA made a mistake in leaving the DTM off its list of series eligible for Formula 1 superlicence points. MITCHELL ADAM asks whether they have a point

Can a touring car series, racing primarily in a single nation, be considered a pathway to Formula 1?

Generally, that's a fairly simple question to answer. If you take the UK as an example, then those who have raced in the British Formula 3 Championship over the past few years will have had their sights far more firmly set on F1 than recent British Touring Car champions Colin Turkington, Andrew Jordan and Gordon Shedden.